What does it cost to convert WebP to JPEG?

$0.003 per call, paid in USDC on Base via x402.

How large can the WebP file be?

Up to 25 MB (26,214,400 bytes). Past a limit the call answers too_large (413).

What happens if the conversion fails?

The tool answers with a typed JSON error from the errors table. Payment is settled only after the tool has produced its result; a call that fails inside the tool is never settled.

catalogue / tools / Images / WebP to JPEG

Convert WebP to JPEG

To convert WebP to JPEG, send one POST to /v1/image-convert with the WebP source and "format": "jpeg" in the body. Each call costs $0.003 in USDC on Base via x402, with no account and no API key. The source file can be up to 25 MB.

Endpoint: POST /v1/image-convert
Price: $0.003 per call
Service: image-convert
Docs: /docs/image-convert

01Limits

Limit	Value
Largest source file	25 MB (26,214,400 bytes)
Timeout	60 s
Source formats	AVIF, GIF, JPEG, PNG, SVG, TIFF, WebP
Output formats	JPEG, PNG, WebP
Option quality	default 80

02Example

A real WebP to JPEG run of image-convert.

Request

POST /v1/image-convert
content-type: application/json
payment-signature: <base64 x402 payload>

{
  "url": "https://grist.tools/samples/images/pair-note.webp",
  "quality": 80,
  "format": "jpeg"
}

Response

200 OK
payment-response: <base64 settlement receipt>

{
  "source_url": "https://grist.tools/samples/images/pair-note.webp",
  "source_format": "webp",
  "format": "jpeg",
  "mime_type": "image/jpeg",
  "width": 556,
  "height": 100,
  "bytes": 4293,
  "image_base64": "/9j/2wBDAAYEBQYFBAYGBQYHBwYIChAKCgkJChQODwwQFxQYGBcUFhYaHSUfGhsj..."
}

Source file: images/pair-note.webp, 248 bytes. Lossless WebP of the same 556x100 raster as ocr-scan.png: two uppercase lines drawn from a hand-written 5x7 bitmap font, SAMPLE SCAN FOR OCR and SECOND LINE 2026. The request sets quality to 80. The recorded run returned 4.2 KB (4,293 bytes) of JPEG, 17.3 times the source size, with an image of 556x100 pixels. Decoded, the JPEG in image_base64 opens with FF D8 FF DB 00 43 00 06 04 05 06 05.

In the sample itself, the RIFF header counts 240 bytes after itself and the one chunk is a lossless VP8L bitstream of 227 bytes for 556 by 100 pixels, with the alpha hint clear. In the returned JPEG: the start-of-image marker is followed directly by a 67-byte quantisation table segment (FF DB), with no JFIF APP0 segment in between: table 0, 8-bit precision, first quantiser value 6.

03Format notes

WebP as a source

WebP can hold lossy or lossless imagery, alpha and animation inside a RIFF container. Grist checks for RIFF at byte zero and WEBP at byte eight; the second test matters because WAV and AVI files also open with RIFF and differ only in that form type. image-convert and ocr-image-to-text each perform the check themselves before any decoder runs. For conversion, sharp opens the file with animated decoding off, so an animated WebP contributes only its first frame, and the header dimensions are compared with the shared pixel budget beforehand. The output does not record whether the source was lossy or lossless: image-convert re-encodes the decoded pixels and drops metadata. A lossless WebP therefore hands exact pixel values to the target encoder, whereas a lossy one passes its own artefacts along.

JPEG as a target

image-convert writes JPEG through sharp with options pinned around the caller's quality value. mozjpeg is off, scans are baseline rather than progressive, chroma subsampling is fixed, coding is optimised, and trellis quantisation and overshoot deringing are both disabled. Fixing these settings means the same image, format and quality produce the same bytes on a given build, instead of drifting with a libvips default. The pixel grid is not resized; only codec and container change, and the response reports the width and height of the result. Because withMetadata is never called, EXIF and similar blocks are dropped. An animated input is opened with animation off, so its first frame is the one encoded. Video frames take another road: video-thumbnail decodes one picture and hands it to ffmpeg's mjpeg encoder, which streams it out through image2pipe.

Note: An animated WebP is converted from its first frame only. JPEG has no alpha channel, so any transparency in the source is lost.

04Errors

Code	HTTP
`invalid_input`	`400`
`blocked_target`	`403`
`unreachable_target`	`424`
`upstream_timeout`	`424`
`unsupported_content_type`	`415`
`too_large`	`413`
`unprocessable`	`422`
`internal`	`500`

When each is raised, and what it means for payment: /docs/image-convert.

05Questions

What does it cost to convert WebP to JPEG?: $0.003 per call, paid in USDC on Base via x402.
How large can the WebP file be?: Up to 25 MB (26,214,400 bytes). Past a limit the call answers too_large (413).
What happens if the conversion fails?: The tool answers with a typed JSON error from the errors table. Payment is settled only after the tool has produced its result; a call that fails inside the tool is never settled.